SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '422c311512a5d170f927871fc941b41a83f569bdc2411e497f912b0091c09cd7' 
  AND token = 'g041+KL/+qlQPDsUfMixVYQJKyiMIGaT5ns/GZYsdmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}